1. Field
The present invention relates generally to telecommunications, and more specifically, to controlling reverse link interference in telecommunications.
2. Background
In a typical telecommunications network based on the CDMA 2000 1xEV-DO standard according to “3rd Generation Partnership Project 2 ‘3GPP2 ’ CDMA2000 High Rate Packet Data Air Interface Specification,” 3GPP2 C.S0024 Version 3.0, Dec. 5, 2001, the control of loading of reverse link traffic from mobile stations or access terminals to a base station is determined by a parameter known as the rise-over-thermal (ROT) ratio.
The reverse links of a CDMA 2000 1xEV-DO system are code division multiplexed (CDM) and are therefore interference limited. In an interference-limited CDM communication system, the reverse link transmission of each access terminal is an interference to other access terminals. An access terminal can transmit at a higher data rate if the interference level from other access terminals is lower. Furthermore, if one of the access terminals transmits at a higher data rate, other access terminals may experience more interference from the access terminal transmitting at the higher data rate.
It is desirable to achieve three major goals in the design of a CDM network, namely, to maximize the overall throughput of the network within any given sector of a base station, to maintain stable reverse link operations, and to ensure coverage at the edge of the network. However, these goals tend to conflict with one another and achieving these goals simultaneously typically requires delicate control of loading within the network.
In many practical situations, the ROT ratio may not be the best indicator of sector loading and may not be relied upon as the sole parameter for controlling the loading of reverse link traffic in order to minimize reverse link interference among the access terminals while providing an adequate data throughput in a wireless communication system. Therefore, there is a need in the art for a new scheme for controlling reverse link loading in a wireless communication system.